GB1265447A - - Google Patents

Info

Publication number
GB1265447A
GB1265447A GB1265447DA GB1265447A GB 1265447 A GB1265447 A GB 1265447A GB 1265447D A GB1265447D A GB 1265447DA GB 1265447 A GB1265447 A GB 1265447A
Authority
GB
United Kingdom
Prior art keywords
oscillator
signal
gate
output
filter
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed filed Critical
Publication of GB1265447A publication Critical patent/GB1265447A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H19/00—Networks using time-varying elements, e.g. N-path filters
    • H03H19/004—Switched capacitor networks

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Stabilization Of Oscillater, Synchronisation, Frequency Synthesizers (AREA)

Abstract

1,265,447. Automatic tuning control of switched filter. C.I.T. COMPAGNIE INDUSTRIELLE DES TELECOMMUNICATIONS. 16 June, 1970 [16 June, 1969], No. 29189/70. Headings H3A, H3Q and H3U. A switching filter whose switching frequency is to be synchronized with a frequency of an input signal has a control loop which comprises: a controlled oscillator 22 providing the switching signal; a phase discriminator 28 fed with the oscillator and filter outputs; and control means for bringing the oscillator within the coverage range of the discriminator and maintaining within that range if the filter output corresponds to predetermined conditions. If the oscillator is not within the coverage range, a logical " 1 " signal Q opens gate 36 to feed a sweep signal from generator 38 to sweep oscillator 22 by varying varactor 23. When the frequency of the oscillator 22 is sufficiently near to the input frequency the output from comparator 28 passes through AND gate 32 to open gate 34 and close gate 36. The comparator output then controls the oscillator in place of the sweep signal. If the level of the rectified filter output is less than a threshold set by 26, or if the error signal from comparator 28 is outside limits set by 30, then the output Q from AND gate 32 becomes " 0 " making Q " 1 " to restart the sweep.
GB1265447D 1969-06-16 1970-06-16 Expired GB1265447A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR6920019A FR2049664A6 (en) 1969-06-16 1969-06-16

Publications (1)

Publication Number Publication Date
GB1265447A true GB1265447A (en) 1972-03-01

Family

ID=9035818

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1265447D Expired GB1265447A (en) 1969-06-16 1970-06-16

Country Status (6)

Country Link
US (1) US3639852A (en)
BE (1) BE751599A (en)
DE (1) DE2029063A1 (en)
FR (1) FR2049664A6 (en)
GB (1) GB1265447A (en)
NL (1) NL7008105A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2143385A (en) * 1983-07-13 1985-02-06 Plessey Co Plc Phase lock loop circuit

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3979691A (en) * 1975-06-30 1976-09-07 International Business Machines Corporation Acquisition process in a phase-locked-loop by switched phase means
IT1156199B (en) * 1978-04-18 1987-01-28 Selenia Ind Elettroniche IMPROVEMENT IN CIRCUITS AUTOMATIC TUNING FOR FILTERS CONTROLLED IN VOLTAGE BY DIGITAL PHASE CONTROL
FR2583937B1 (en) * 1985-06-21 1987-08-07 Saphymo Stel FILTERING CIRCUIT WITH CHARACTERISTIC FREQUENCIES LINKED TO THE FUNDAMENTAL SIGNAL OF THE FILTER
US5438304A (en) * 1990-12-19 1995-08-01 Jennings; Peter R. Automatically tuned notch filter for providing bandpass and band reject signals

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL272204A (en) * 1961-02-01
FR1494257A (en) * 1966-07-26 1967-09-08 Cit Alcatel Preset frequency synthesizer

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2143385A (en) * 1983-07-13 1985-02-06 Plessey Co Plc Phase lock loop circuit
US4596963A (en) * 1983-07-13 1986-06-24 Plessey Overseas Limited PLL with lock up detector and lock acquisition circuit

Also Published As

Publication number Publication date
US3639852A (en) 1972-02-01
BE751599A (en) 1970-12-08
NL7008105A (en) 1970-12-18
FR2049664A6 (en) 1971-03-26
DE2029063A1 (en) 1971-01-07

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Legal Events

Date Code Title Description
PS Patent sealed [section 19, patents act 1949]
PCNP Patent ceased through non-payment of renewal fee